Porphyria Flashcards
The synthesis of which compound is disrupted in porphyria?
Heam
What does the build up of porphyrins affect?
Skin
Nervous system
What enzyme is deficient in porphyria cutanea tarda (PCT)?
Uroporphyrinogen decarboxylase
What enzyme is deficient in porphyria erythropoietic protoporphyria?
Ferrochelatase
What enzyme is deficient in porphyria acute intermittent porphyria?
Porphobiliogen (PBG) deaminase
What metabolite builds up in porphyria cutanea tarda (PCT)?
Uroporphyrinogen III
What metabolite builds up in erythropoeitic protoporphyria?
Protoporphyrin
What metabolite builds up in acute intermittent porphyria?
Porphobilinogen
What is the commonest porphyria?
Porphyria cutanea tarda (PCT)
What causes porphyria cutanea tarda (PCT)?
Genetics (congenital PCT)
Liver damage
How does porphyria cutanea tarda (PCT) present?
Skin fragility and photosensitivity
Hyperpigmentation and thickening of skin
Excessive hair growth
What investigations can be done in porphyria cutanea tarda (PCT)?
Urine Wood’s lamp
urine glows due to excess porphyrins
How does erythropoietic protoporphyria present?
In childhood with photosensitivity causing swelling, blistering and scarring
What investigations can be done in erythropoietic protoporphyria?
RBC Wood’s lamp
RBC glow due to excess porphyrins
How is erythropoietic protoporphyria treated?
Avoidance of sun
Sunscreen
Anti-oxidant supplements
Phototherapy (TL-01)